Passing or back-up tongs



B. P. HOFFMAN PASSING QR BACK-UP TONGrS April 10, 1928.

Filed Dec. 18. 1926 m f u H E I I afzwmqJ Patented Apr. 10, 1928.

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BENJAMIN 1?. HOFFMAN, OF'TULSA, OKLAHOMA; ASSIGNOR TO THE PIERCE DEVELOIB MEN'T COMPANY, OF TULSA, OKLAHOMA, A CORPORATION OF OKLAHOMA.

' PASSING on BACK- r Tones.

"1 Application filed beceniber 18, 1926; Serial no. 155,618.

v In handling pipe and tubing in the oil fields, both when moving-thesame from place to place or coupling or uncoupling the lengths, a toolis utilized and is generally designated as a passing or back-up tongs.

It is a primary object of this invention to provide-a toolof thecharacter aforesaid which may be readily manipulated by one, person,under certain conditions, or by ,two persons, as occasion may require,and which admits of the movable jaw being readily replaceable when worn,the'movable handle automatically locking to prevent released the pipe orlike part when the jaws have become worn to necessitate replacement.

The invention consists of a tool of thenature statedembodying a frameprovided with a pipe receiving recess which is toothed to positivelygrip the pipe or like part, a fixed frame, a movable i handle at one endof the v handle pivoted to the opposite end of the frame. and a pivotedjaw operable means of the pivoted handle and adapted togbecomeautomatically locked when the gripping teeth have been worn to renderthe efficiency of the tool doubtful.

While the drawings illustrate a preferred embodiment of the invention,it is to be understood that in adapting the means to meet specific needsand requirements thedesign may be varied and such other changes in theminor details of construction may be resorted to within the scope of theinvention as claimed, without departing from the spirit thereof.

For a full understanding of the invention and the merits thereof,reference is to be had to the following description and the drawingshereto attached, in which,

Figure 1 is a top plan View of a passing or back-up tongs'embodying theinvention,

parts being broken away.

Figure 2 is a front. view of the tool, parts of the handle being brokenaway.

Figure 3 is a fragmentary view showing the pivoted jaw locked after the;teeth have become worn.

Figure 4 is a sectional 4:-4 of Figure 1. 7

Corresponding and like parts are referred to in the followingdescription and designated in the several views of the drawings by likereference characters.

The tool comprises a frame 1 which may consist of a casting or a forgingand this view on, the line of the toolin its continued use.

, frame is elongated and provided at one'endf the pipe or like part tobe gripped.

The movable jaw 5 is toothed, as indicated. at 9, and is pivoted at oneend within the slot' i, and the toothed portion is adapt- I ed to beprojected into the recess 7 soas to,

act jointly with the teeth 8 togrip the pipe a or other part received inthe recess ;7.- A11 7 arm 10 projects outwardly from the; pivotal end ofthe jaw v5 and the inner end of the movable handle is disposed tooperate in' the space formed between the arm 1O and aw 5. Forconveniencea socketll is pro vided to receive the handle 6 and, in effect may beconsidered as a part there'of a-nd'is included when reference is made tothe hane dle. The arrangement admits of the part 6 n being detached fromthe socket '11 when required for any purpose. The inner end of thehandle is eccentric to the pivot 12 and provides a cam 13 whichisadapted to ride upon the outer face of the pivoted jaw 5 to move thelatter into thework-receiving recess 7 so as to grip the pipe or otherpart to be held. a A projection 14 is formed upon the rear side of thelever. and is adapted to ride upon the arm 10 and withdraw the jaw 5when it is required to releasethepipe or other part previously gripped.A recess 15 is formed in the rear side of the leveradjacent theprojection 14: and when thejawj 5 has been advanced to the'limit of itsmovement said recess receives a projection 16 at 9 the outer end of thejaw, thereby forming a lock to prevent release of the jaw in theaccustomed way in the ordinary use of the tool, thereby indicating tothe workman that the gripping teeth 8 and 9 have become so worn as tonecessitate replacement in order to 'insure the efficiency and positiveaction Under this condition the pivoted jaw may be released by removalof its pivot 17 or the pivot 12 of the handle 6, itbeing understood thatthese pivots may consist of bolts, as clearly illustrated, or may be ofany determinate construction. The outer or rear face of the pivoted jaw5 is preferably curved to conform to the out- 30' medi ate; wo k Ire 1mgfftlief1cahi113ftoadn1itof tig hiaeeoa tainingan extended bearingthereon." :When

7 the outer end, of the pivoted handlefi is movednutwardlyfi-omtheiframe the jaws" '6 is drawnint'o the slot t, hythe projection14 riding upon the inner face of the arx n 1 and when the handle 6 ismoved toward the I frame the j aw is proiecte dinto the Wor hrece vingrecess 7 by the cam 13' riding upon the outer or rear face of the jaw,as W111 be readilyf pp i te'cli v I Hating th'us' described theinvention,' I clairi'izij 1 A; tool; o f thefcharacter specified com-1-5 i pifi sing afflfanje having a Work receiving re- I a'slot vat one sdefof said recess, a

ces's and jaw p voted atf'one endflvithin't-he slot and h having aprojection at its: ,oiitei' end, arm a 4 projecting'froni the'pivot'al'end of thejjaw, ancla l ever pii oted withinfsaid slot and lop- Qerat ing between the j aw and the arinproject ingthe'refrom; andhhavingtaprojection to coactwith the'arinand a recess adjacenteaid vprojection toreceive the projection at the v outer .end of the jaw and automaticallylock the jaw when projected into the work-re V ceivingrec se to thelirnitcf its throw.

, 2 Au pii iilg' xilelcngatd :r 'ame hav g an t ap'i epgi. grtienj toone side ime said, Work 'reiceiying'grecfes, a handle fitted to: theopposit', endbffthef frame, a jawpivot'ed at of ofj the"characterspecified coin H H o t t han e celv ngrecess, and a slot11};

one; end Within the said slot and having its rear side curwed ai idformed with elf terminal locking projection, an arm projecting from t-lipivotal endof the wand operating lever 'pivoted within' the sa id slotand having its inner e idOf eccentric formation to provide acainforprojecting the pivoted ja 'sai l leyer operating between the jaw arfdthe arm thereof and having a terminal project-ion and a recess adjacentsaid projectipiitoreceive the projection of the wall I 5123i dhandle'piibtrliivithin the Slotted end of the frame and: extending in' anopposite it"s 'pii otzilj 'encl i 1 a locking element; and:

a a jaw pivoted slotte tl, endf of the 1 af terminal locking element toan hii" Y}; 7 TI .1 tis m l vjwllered l ifi im gn ur BENJAMIN RHOEEMANILi frame and operable byth elpivotecl handle 60' 7 no elefrnenfi o1the'pi't V a t r u, H yli k i d n' t e V jaft v he' the latterisfattheflimit ofits v a direction i) the fixed and formed at

